Knife-protector for shoe-stitching machines



A. M. WIRTH.

KNIFE PROTECTOR FOR SHOE STITCHING MACHINES.

APPLICATION FILED JUNE 9.1920.

1,387,673. Patented Aug. 16, 1921.

I N VEN TOR.

A.M WZJ'ZIZ/ BY B S Q t ATTORNEY UNITED STATES PATENT OFFICE.

ANTONE I. WIBTH, OF STOCKTON. CALIFORNIA, ASSIGNOR OF ONE-HALF TO FRANK J. MACKEY, OF STOCKTON, CALIFORNIA.

KNIFE-PROTECTOR FOR SHOE-STITCHING MACHINES.

Application filed June 9, 1920.

To all 211710212 it may concern Be it known that I, lxroxn M. \Vnrrn, a citizen of the United States. residing at Stockton, in the county of San Joaquin, State of California, have invented certain new and useful Improvements in Knife- Protectors for Shoe-Stitching Machines; and I do declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings. and to the characters of reference marked thereon. which form av part of this application.

This invention relates to improvements in devices to protect the knife carried by shoe stitching machines and positioned thereon a short distance ahead of the needle.

lVhen stitching new work such as shoe soles. the knife is necessary to groove or indent the leather previous to the application of the thread.

Vhen repairing old shoes however, not only is the necessary groove already present, but having been in contact with the ground, the groove is very apt to be filled with fragments of stone, gravel, and other gritty and abrasive materials which of course soon dull the knife and render it unfit for further service.

Since a large percentage of shoe repair work is done on worn materials, it becomes necessary to protect the knife so that it cannot come in contact with the material being repaired.

I know that devices for this purpose have been tried out, and some are on the market, but as far as I am aware they all necessitate the moving of the knife. This latter having a certain definite and fixed relation to the needle, every time it. is moved back to position after being protected necessitates the careful adjustment thereof, which consumes much valuable time. especially if this is done several times a day. as is frequently the case.

The principal object of my invention therefore is to provide a knife protector which will adequately shield the knife when necessary, and without the necessity of moving the knife from its permanent and fixed position.

Another object is to provide such a device which may be attached to the machine with Specification of Letters Patent.

Patented Aug. 16, 1921.

Serial No. 387,697.

out the necessity of making any changes, or drilling any additional holes, etc., in the machine itself, and yet which, when protecting the knife, will have no tendency toward horizontal movement which might cause the needle to strike thereon and become bent or broken. At the same time it is a matter of but a few seconds time to move the protector away from the plane of the knife without actually removing it from the machine, so that the knife may be used.

Also the knife must be protected or held out of action when working on either new or old rubber or composition soles, since a knife cannot be used on the latter without splitting the same.

A further object of the invention is to produce a simple and inexpensive device, and yet one which will be exceedingly effective for the purposes for which it is designed.

These objects I accomplish by means of such structure and relative arrangement of parts as will fully appear by a perusal of i the following specification and claims.

In the drawings similar characters of reference indicate corresponding parts in the several views.

Figure 1 is a front elevation, in dotted outline. of the portion of a stitching machine adjacent the needle and showing my improved protector mounted in connection with the needle-knife plate.

Fig. 2 is a. vertical section of the device detached.

Fig. 3 is a top plan view of the same.

Fig. 4; is :1V cross section taken on a line el--t of Fig. 3.

Referring now more particularly to the characters of reference on the drawings, the numeral 1 denotes the shuttle door of the machine. covering the shuttle mechanism, on top of which is rigidly mounted a plate 2 having a short knife 3 formed therewith and positioned in the plane of the needle 4.

The usual presser foot 5 is mounted above the plate 2, and is adapted for ver tical movement relative thereto.

The foregoing number and arrangement of parts is standard on certain types of shoestitching machines. I

My device consists of a metal strip 4 6 whose upper end 6 is adapted to rest on the plate 2 and is provided. with a slot 7 of a length and width sullicient to receive the knife 3 therein and to allow of the free passage of the needle 4 therethrough. The metal of the member 6 is of a thickness somewhat greater than the height of the knife 4,

having a hole 9' slotted lengthwise of the knife 3.

The foot 9 rests on a boss it) formed with the machine, and the hole is adapted to take the bolt or cap screw 11 Pl'OjGL-tll'll]; into the boss and forming a part of the machine as originally equipped. By reason of this slot ted hole, the member 6 may be adjusted over the knife to fit should the boltll in one machine be slightly farther from the knife than in another, or should the location of the slot 7 vary somewhat.

The end of the portion (3 opposite the curved portion? is curved downwardly for the full width thereof beyond the knife plate 2 to form a flangeor lip 12 adapted to rest against the side of the said plate. On the oppositeside of said plate, the member 6 is punched transversely to form integral. lugs 13, which are projected downwardly in a plane to. bear against that side of the plate 2. Thus the device is firmly held in position relative to the plate against any possibility of horizontal movement relative thereto. i I

The front or outer edge of the portion 6* is curved downwardly as at 14, so that a smooth and non-cutting surface will be presented to the shoe being stitched.

In order to move the devi'e to one side to permit the knife to be used, it is only neces sary to loosen the bolt 11 somewhat, lift the device enough. so that the members 12 and 13 clear the plate 2, and then swing it around over the shuttle-hood back of the door 1.

From the foregoing desoription it will be readily seen that I have, produced such a device as substantially fulfils the object of. the invention as set forth herein.

While this specification sets forth in detail the present and preferred construction of the device still in prar tice such deviations from such detail may be resorted to as do not form adeparture from the spirit of the invention, as defined by the appended claims. Having thus described my invention what I claim as new and useful, and desire to secure by Letters Patent is i. In a shoe stitching machine, the combination with the shuttle door, a. needle knife plate thereon and a vertical pivotal bolt on the machine on one side of the door; of a plate projecting over the knife-plate and provided with a slot in which the knife is inclosed, and an arm formed with the plate and projecting down alongside the door to said bolt thereof and being pivotally held by the latter.

2. In a shoe stitching'machine, the combination with the shuttle door, a needle knife plate thereon, a boss on the machine to one side of the door and a vertical cap screw in said boss; of a plate adapted to project over and rest on the knift-plate and provided with a slot adaptedto inclose the knife, an arm extending from the plate downwardly alongside the door, and a foot resting on the boss, the foot being provided with a slotted hole extending in a plane parallel to the slot in the plate and through which therap screw projects.

3. In combination with the needle knifeplate of a shoe stitching'machine, a protector plate adapted to rest on the knife plate and provided with a slot to surround the knife, flanges on the protector plate engag-inc both sides of the knife-plate and means whereby the protector plate may be swung entirely clear of the knife plate, said protector plate being secured to the machine independent of the knife plate.

l. A knife protector for shoe-stitching machines comprising a plate adapted to rest on the knife-plate of the machine and having a'slot adapted to receive and conceal the knife, said firt named plate bending down alongside the shuttle-door of the machine and being pivoted to the frame of the machine on a horizontal plane, whereby on raising the protecting plate to clear the knife it may be swiveled to one side of said knife.

5. In combination with the needle knifeplate of a shoe stitching machine, a protector plate adapted to rest on the knife-plate and provided with a slot to surround the knife,

and means inde iiendent of the knife plate whereby the protector plate may be rigidly held in place while permitting the same to be loosened and swung free of the knife plate.

In testimony whereof I affix my signature.

ANTONE M. vvln rn." 

